What Specs Matter on a Fab Lab Laser Cutter?
The laser cutter in a fab lab or makerspace is usually a CO2 laser, specified by tube power in watts, bed size, and the exhaust system attached to it. It is the machine most members want and the one institutions write the most policy around, because university environmental health and safety programs treat shop lasers as both a fire risk and a fume source. This page explains the spec-sheet vocabulary — not how to operate one, which is what a lab's own training exists for.
Why the laser is the anchor tool
The standard fab lab inventory was built around a small set of machines that cover most of digital fabrication, and the laser cutter sits at the center of it: fast, forgiving, and useful for everything from press-fit construction kits to enclosure panels. Neil Gershenfeld's account of how the labs and their tool set came together is in How to Make Almost Anything, and the Fab Foundation's getting-started guidance covers how the inventory is planned and budgeted for a new lab. For the full machine list, see what equipment a standard fab lab has.
CO2 vs. fiber
These are different machines for different jobs.
- CO2 lasers work at a far-infrared wavelength absorbed well by organic and non-metallic materials: plywood, MDF, acrylic, paper, card, leather, fabric, rubber. This is the general-purpose lab machine.
- Fiber lasers work at a near-infrared wavelength absorbed by metals. They mark, engrave, and — at higher power — cut metal, but they are poor at acrylic and most plastics.
A lab with one laser nearly always has a CO2. A fiber laser is a second machine bought for a specific need, not a replacement.
The numbers on the spec sheet
- Tube power (watts). Higher wattage means thicker cuts and faster passes, not fundamentally different capability. It is the single biggest driver of price.
- Bed size (work area). Determines the largest sheet you can process in one job. Worth checking against the standard sheet stock your region actually sells, since re-cutting every sheet to fit wastes material and staff time.
- Z-axis travel and pass-through. Travel sets how thick a part can sit in the machine; a pass-through door lets long stock cross the bed.
- Kerf. The width of material the beam removes. It matters enormously for press-fit and finger-joint design, because every slot comes out slightly wider than drawn. Labs usually publish a measured kerf for their machine and material.
- Lens focal length. Shorter focal lengths focus to a finer spot for detail and thin stock; longer ones hold focus deeper into thick material.
- Air assist. A directed air stream at the cut point that reduces flare-up and flaming and clears debris from the kerf.
- Exhaust and filtration capacity. Rated in airflow; either ducted outside or run through a filtration unit.
- Chiller. Water-cooled tubes need one, and its capacity is part of the machine's real footprint and power draw.
Extraction is part of the machine, not an accessory
A laser cutter is not a standalone purchase. Cutting generates smoke, fine particulate, and vapor that must be captured and removed, and the beam-and-fire hazards come with the equipment. The University of Washington's laser cutter safety guidance sets out how shop and makerspace lasers are handled institutionally, including beam exposure, fire risk, and fume and particulate ventilation. Institutional makerspace policies follow suit — Binghamton University's makerspace safety program is a published example of how a lab writes equipment-specific rules, authorization tiers, and supervision requirements around machines like this.
Two consequences for anyone comparing machines on price: the ducting, blower, or filter is a real line item, and the room has to be able to accept it. A space without an exterior wall route or an acceptable filtration budget does not have a laser cutter, it has a crate.
Materials policy
Every lab maintains an approved-materials list, and the hard prohibitions are about chemistry rather than difficulty — PVC and other chlorine-containing plastics are standard entries on the forbidden list, along with unknown plastics and anything coated or treated with an unidentified finish. Expect the lab to require you to identify your stock before it goes in the bed. How those approvals and machine authorizations are granted is covered in how makerspaces structure equipment training and access.